Hobbs resident Elgin Vine, 21, was arrested and charged with an open count of murder Tuesday morning. He remained in the Lea County Detention Facility on $250,000 bond.

Martinez, 26, died early Monday after being shot once in the forehead as he stood in the doorway of his home. Preliminary results from the autopsy released Tuesday state that Martinez died of a gunshot wound to the head.

Police Capt. Mike Emerson said the victim was standing behind a screen door at the time of the shooting. The bullet apparently ricocheted off of the door's frame before hitting Martinez squarely in the forehead.

In addition, police believe the suspect was aiming at a witness who was running away from the gunman's vehicle not at Martinez.

''Sammy just happened to be in the wrong spot at the wrong time,'' Emerson said. Still, ''They all know each other. It's not like we don't know who these guys are.''

Monday morning's shooting happened after two men driving toward South Elm Street in a van noticed they were being tailed by a small green car, Emerson said in a written release.

When the van pulled over, the driver of the green car, identified by one witness as being Vine, pulled alongside as the car's driver and lone occupant produced a handgun, the release states.

One of the witnesses recognized Vine, saw the weapon and ran from the van as the suspect fired between one and three shots through the passenger window of the car, Emerson said.

Having missed the target, the car drove off, and police later arrived to find Martinez lying face down on the porch of the Elm Street house where he and the witness apparently lived.

The witness did not give police a possible motive for the shooting, Emerson said. The second witness, who stayed behind in the van, did not recognize Vine but said he heard three shots fired.

Also missing Tuesday, he said, was a murder weapon.

Investigators discovered a .45-caliber pistol in a possible getaway car found at a Hobbs motel several hours after the 1:30 a.m. shooting, Emerson said. The weapon had been reported stolen fro m Seagraves several weeks earlier.

But bullet fragments recovered during Tuesday's autopsy in Albuquerque did not appear to be from a .45-caliber weapon, Emerson said.

''There was probably another gun used and it was tossed,'' he said. ''He had plenty of time to hide it.''